Injunction is either a technical legal word or very literary. These are the OED's most recent examples.
1667 Milton Paradise Lost x. 13 The high Injunction not to taste that Fruit.
1766 O. Goldsmith Vicar of Wakefield I. x. 91 My wife always generously let them have a guinea each..but with strict injunctions never to change it.
1793 J. Boswell Principle Corrections Life Johnson 2/1 The emphasis should be equally upon shalt and not, as both concur to form the negative injunction.
1849 Macaulay Hist. Eng. II. vi. 153 In spite of all injunctions of secrecy, the news..had spread fast.
1898 F. Montgomery Tony 19 Forgetful of his Mother's parting injunctions.
